Rail braces are utilized to buttress railroad rails against the side thrusts of the rail traffic tending to overturn them. When a rail is overturned, the head of the rail is rotated about its origin to a position in which it is angularly offset with respect to a straight line extending through the vertical axis of the rail. The head of a rail may rotate with respect to the base of the rail because the base is not anchored or affixed to the rail ties. Therefore, the head of the rail which supports the traffic load is free to move. Rotation of the rail head even to a small degree is undesirable because if a lateral load is applied to the head of a rail over a relatively long length of rail, it is possible that the lateral load may cause the entire rail to roll over and ultimately collapse.
A rail brace supports a rail and resists lateral movement of the head of the rail by having an upper surface which bears against a fishing surface formed on the underside of the head of the rail and a lower surface which bears against a fishing surface formed on the top side of the base of the rail on the side of the rail opposite that engaged by the flange of a car or locomotive wheel. Traditionally, some braces have been anchored by being spiked to a wooden tie. However, rail braces anchored in this manner eventually loosen and it has been necessary to periodically tighten the brace so that it firmly engages the base and head of the rail. Where a brace has been spiked to a tie, it becomes necessary to remove the spikes and redrive them in order to retighten the brace. Eventually, the tie must be replaced because it has been "spike killed".
Because of the disadvantages inherent in fixed rail braces, adjustable braces were developed which eliminated the need to respike the brace assembly each time the brace was tightened. In one type of adjustable brace, one side of the base of the brace is set at an angle and this side directly engages a stop on the tie plate set at a similar angle to thereby provide a wedging action of the brace between the rail and the stop. In another type of adjustable brace, a wedge is interposed between the brace and the stop secured to the tie plate. In both of these assemblies the brace must be driven into frictional engagement with the stop or the wedge to firmly secure the brace into abutting contact with the rail. After the wedge or brace in these assemblies has been driven into position, the brace may be secured by bolts, nuts or lag screws. In some instances, the wedge member has been secured by having a cover plate that is secured by bolts to the tie plate engage the wedge member or the wedge member and the brace to thereby secure these elements. One problem which has been experienced where bolts, nuts or lag screws are utilized to secure adjustable braces resides in the fact that it has been found necessary to periodically inspect the braces to determine if they have remained in firm contact with the rail. Where looseness of the brace has been observed, trackwork maintenance personnel must loosen the fasteners, drive the wedge or brace into firm engagement with the rail and thereafter resecure the fasteners. Such inspection and tightening of braces by track personnel has greatly increased the cost of maintaining rail lines. Additionally, such maintenance practices necessitate the use of relatively skilled maintenance personnel who must be able to determine the proper degree of tightness for a rail brace.
Because it has been found time consuming and expensive from a maintenance standpoint to utilize bolts or lag screws to secure rail braces, the railroad industry has begun to utilize elastic fasteners such as spring clips to bias adjustable rail braces against stock rails. In one type of adjustable brace assembly utilizing an elastic fastener, one side of the base of the brace is set at an angle with respect to the surfaces on the rail which engage the brace and the angled side of the base engages a stop mounted on the tie plate having a complimentary angled face to thereby provide a frictional wedging action for urging the brace against the rail. In this assembly the elastic fastener biases a cover plate downwardly against a flat surface formed on the top of the brace to prevent vertical and horizontal movement of the brace. The surface on the brace may be corrugated and engage a similarly corrugated surface formed on the bottom of the cover plate to further inhibit longitudinal movement of the brace. In this assembly the axis of the elastic fastener has been made nonparallel to the surfaces of the rail brace which engage the stock rail. One problem with having the axis of the fastener nonparallel to that of the rail is that automatic equipment utilized to install such fasteners normally only can install these fasteners if the axes of the fasteners are parallel to that of the rail. If the axes are not parallel to the rail, the fasteners must be installed manually.
It has been found that where an elastic fastener has been utilized to clamp or lock a cover plate against a horizontal surface on a rail brace, vibration and movement of the rail may cause the rail brace to loosen. This occurs because as the traffic passes over the rail, the rail and the brace may move vertically downwardly and momentarily move out of contact with the cover plate. As a result, the top surface of the brace tends to separate from the cover plate and the brace and cover plate are no longer locked together. Over a period of time, the rail brace may move horizontally with respect to the cover plate and move away from the rail.
Recently, legislation has been enacted deregulating the rates set by railroads for transporting freight. Accordingly, this has forced the railroads to become more competitive with trucks and with each other. As a result, railroads have been forced to discontinue using duplicate lines of track. This has resulted in a reduction of the railroad labor force through early retirements and normal attrition. Resultantly, the remaining labor force has become less experienced and less skilled than the railroad maintenance force of the past. Thus, railroad trackwork component suppliers have been encouraged to provide products having fewer parts, easier installation, and less maintenance.
Accordingly, it has been found desirable to provide a rail brace that has fewer parts, that may be retained in position by an elastic fastener, that can be installed with a minimum of effort and knowledge by inexperienced workmen and which requires no maintenance.